Recently, as image sensors, such as CCDs, CMOSs, and the like, very small image sensors with increased pixel count have been known. Along with this, downsized imaging device bodies equipped with these image sensors have also been known, and with respect to the imaging lenses for use with these imaging device bodies, those downsized while maintaining favorable optical performance are applied. In the mean time, in the applications of surveillance cameras and in-vehicle cameras, those equipped with a small imaging lens yet having a wide angle of view and high performance have been known.
As imaging lenses having a wide angle of view with a relatively small number of lenses known in the aforementioned fields, those described, for example, in Japanese Unexamined Patent Publication No. 9 (1997)-281387, Japanese Unexamined Patent Publication No. 2 (1990)-284108, Japanese Unexamined Patent Publication No. 2005-316208, and Japanese Unexamined Patent Publication No. 2011-128210 may be cited.